The acai (pronounced "ah-sigh-EE") berry diet involves the consumption of acai supplements, most commonly for weight-loss purposes. The acai berry is the fruit of the acai palm tree (Euterpe oleracea), which is native to tropical Central and South America. Although it is possible to eat the soft interior stem (the palm heart), the acai plant is better known for its reddish-purple fruit.

Acai has been a traditional food of Amazon natives for hundreds of years. Acai beverages are prepared by extracting juice from the fruit's pulp and skin. Scientific research on acai fruit has focused on its antioxidant properties, which are reported to exceed those of other antioxidant-rich foods like blueberries and pomegranates.

Acai fruit has also shown anti-cancer and anti-inflammatory activity in laboratory studies. However, there is currently insufficient evidence available to support the use of acai for any health-related conditions in humans.

Advocates of the acai berry diet claim that the antioxidants in the berries enhance general well-being and vitality, which may in turn support weight loss. Promoters of the diet say that the berry has a combination of essential fatty acids, amino acids, and phytosterols that work in unison to improve metabolism, enhance digestion, and reduce appetite. The acai berry diet is often paired with a colon-cleansing product, or with other nutritional ingredients that are said to enhance weight loss. However, claims made for rapid weight loss without accompanying lifestyle modifications are unsubstantiated. There is a lack of credible evidence showing that acai berry supplementation alone promotes weight loss.

The acai berry diet gained popularity after it was coined the "number one superfood for better health and anti-aging" in 2007 on the Oprah Winfrey Show. It was widely publicized in the media that both Oprah Winfrey and Rachel Ray lost weight using acai berry supplements, although it is not clear if these claims were verified. A multitude of manufacturers and distributors have capitalized on this publicity by selling acai berry supplements with their own unsubstantiated health claims. Oprah Winfrey has since sued many of these companies for using her name without permission to endorse their products.

It is important to purchase acai products from a reputable source, such as a trusted natural food store. There are many reports of scams, however, with some online companies illegally billing their customers for "free" trials of acai berry products. After canceling their free trials, thousands of these consumers have had trouble stopping recurrent credit card charges from being submitted by these companies. Some Web sites that warn about acai-related scams are themselves untrustworthy. Many acai supplement companies have "F" satisfaction ratings from the U.S. Better Business Bureau.

Weight loss: There are many claims that acai berry supplements cause rapid weight loss. While these claims are difficult to substantiate, acai berries do contain healthful constituents that could aid in a weight loss program that is based on proper nutrition and exercise. In particular, acai berries contain healthy fats, including omega-3 and omega-6 fatty acids, which may increase the body's metabolism, enabling it to burn unwanted fat stores. Acai berries also contain high levels of fiber, which aid in digestion and may make an individual feel fuller for a longer period of time. In addition, the acai berry is rich with amino acids, which the body uses to build muscles and to stay healthy. The phytosterols found in acai may lower cholesterol levels.

Other uses: Scientific research on acai fruit has centered on its potential antioxidant properties. Acai fruit has also shown anti-cancer and anti-inflammatory activity in laboratory studies. Currently, there is insufficient available evidence to support the use of acai for any health-related conditions in humans.

The acai berry diet involves incorporating commercially available acai supplements, juices, powders, or dried fruit into one's diet. The fresh fruit is usually not available because it spoils within a few days after it is harvested.

Marketers of acai supplements offer many blends of acai that contain additional "anti-aging" antioxidants; these products typically include herbs that are advertised to support weight loss. For example, one Web site sells a "Weight Loss Trifecta," consisting of acai berry, a colon-cleansing supplement, and resveratrol (an antioxidant).

The acai berry diet is often advocated as a weight-loss strategy. However, it is not clear what the most effective dose may be. Additionally, there is a lack of credible evidence showing that acai berry supplementation alone promotes weight loss. Consumers are encouraged to meet with their physicians and/or dietitians before making any drastic dietary changes.

According to various secondary sources, users have typically consumed 1-2 daily cups of tea; this tea has been derived from the roots of the acai palm tree. The daily consumption of about 100 grams (3.5oz) of frozen acai pulp has also been anecdotally recommended. Many Brazilians drink up to one liter (34oz) of acai juice daily. Additional recommended doses from secondary sources include: 1oz of acai powder mixed with 10-12oz of water once or twice daily, or 1-2 grams of freeze-dried acai in capsules or tablets daily.

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.